COMPUTER ANALYSIS OF DISEASE DATA TO DERIVE HYPOTHETICAL GENOTYPES FOR REACTION OF HOST VARIETIES TO PATHOGENS

1971 ◽  
Vol 13 (4) ◽  
pp. 742-748 ◽  
Author(s):  
W. Q. Loegering ◽  
R. A. McIntosh ◽  
Coleman H. Burton
Keyword(s):  
Boolean Algebra ◽  
Computer Program ◽  
Leaf Rust ◽  
Visual Inspection ◽  
Puccinia Recondita ◽  
Wheat Leaf Rust ◽  
High Infection ◽  
Wheat Leaf ◽  
Infection Types ◽  
Genotype A

A method is described for deriving genotypes for low reaction in varieties of a host from data resulting from inoculating many host varieties with many cultures of a pathogen. A computer program utilizing Boolean algebra was used to compare and group patterns of low and high infection types produced by host variety: pathogen culture combinations. Visual inspection within each group allows derivation of the genotype. A successful trial of the system was made with data on wheat leaf rust involving 60 varieties of wheat and nine cultures of Puccinia recondita.

THE INHERITANCE OF RESISTANCE IN RYE TO Puccinia recondita f. sp. secalis and f. sp. tritici

1984 ◽  
Vol 64 (3) ◽  
pp. 511-519 ◽  
Author(s):  
G. L. C. MUSA ◽  
P. L. DYCK ◽  
D. J. SAMBORSKI
Keyword(s):  
Disease Resistance ◽  
Leaf Rust ◽  
Secale Cereale ◽  
Single Gene ◽  
Inbred Lines ◽  
Puccinia Recondita ◽  
Wheat Leaf Rust ◽  
Susceptible Parent ◽  
Seedling Resistance ◽  
Wheat Leaf

The inheritance of seedling resistance to isolate RLR 213/78 of rye leaf rust (Puccinia recondita f. sp. secalis) and race 30 of wheat leaf rust (P. recondita f. sp. tritici Rob.) was investigated in six inbred lines of rye (Secale cereale). Inbred line UM8116 was used as the susceptible parent in crosses. Inbred lines UM8003, UM8071 and UM8301 each have a single gene and UM8336 and UM8340 each have two genes for resistance to rye leaf rust. For resistance to wheat leaf rust UM8071 has a single gene, UM8003 and UM8340 each have two genes and UM8301 and UM8336 each have three genes. UM8295 is heterogeneous for reaction to both rusts. One of the genes in UM8340 may condition resistance to both rusts. The genes for resistance to RLR 213/78 appear to be independently inherited while some of the genes conferring resistance to race 30 may be identical or very closely linked. The potential of rye as a source of disease resistance for wheat and triticale improvement is discussed.Key words: Secale cereale, disease resistance, wheat leaf rust

Molecular and virulence diversity and linkage disequilibria in asexual and sexual populations of the wheat leaf rust fungus, Puccinia recondita

Genome ◽  
1998 ◽  
Vol 41 (6) ◽  
pp. 832-840 ◽  
Author(s):  
J Q Liu ◽  
J A Kolmer
Keyword(s):  
Leaf Rust ◽  
Rust Fungus ◽  
Field Population ◽  
Puccinia Recondita ◽  
Wheat Leaf Rust ◽  
Asexual Population ◽  
Sexual Population ◽  
Linkage Disequilibria ◽  
Wheat Leaf ◽  
Virulence Diversity

An asexual field population and a sexually derived population of the wheat leaf rust fungus, Puccinia recondita, were examined and compared for diversity and linkage disequilibria between virulence and molecular phenotypes. Isolates in both populations were tested for virulence to 20 Thatcher wheat lines near-isogenic for leaf rust resistance genes, and for random amplified polymorphic DNA (RAPD) variation using 10 DNA primers. In the asexual field population, 36 virulence phenotypes and 14 RAPD phenotypes were identified in 43 isolates. In the sexual population, 87 virulence phenotypes and 79 RAPD phenotypes were identified in 104 isolates. Linkage disequilibria was less in the sexual population compared to the asexual field population. Virulence-RAPD phenotype pairs (110 in total) were directly compared between the two populations for association. In the asexual population, 39 virulence-RAPD phenotype pairs were associated (P < 0.05), compared with 18 pairs in the sexual population. Linkage was not evident, as some residual disequilibria remained between virulence and RAPD phenotypes. In the asexual population 18 RAPD phenotype pairs were associated, compared with 9 pairs in the sexual population. The sexual population was also tested for RAPD variation with an additional six primers. In the sexual population, amplification sites of four different primers were tightly linked which indicated a chromosomal segment in P. recondita may not readily undergo recombination. Disequilibria between virulence and RAPD phenotypes in field populations of P. recondita in Canada is maintained by asexual reproduction.Key words: Puccinia recondita, molecular diversity, virulence diversity, linkage disequilibria, wheat leaf rust.

Control of wheat leaf rust with 4-n-butyl-1,2,4-triazole

1975 ◽  
Vol 15 (73) ◽  
pp. 276 ◽  
Author(s):  
RG Rees ◽  
GJ Platz
Keyword(s):  
Leaf Rust ◽  
Field Experiments ◽  
Puccinia Recondita ◽  
Wheat Leaf Rust ◽  
Yield Increase ◽  
Boot Stage ◽  
Crop Development ◽  
Wheat Leaf ◽  
Puccinia Recondita Tritici ◽  
Excellent Control

The control of wheat leaf rust (Puccinia recondita tritici) by seed or foliar applications of 4-n-butyl-l,2,4-triazole (RH-124) has been examined in field experiments over three years at Gatton, Queensland. Single foliar sprays of RH-124 at rates as low as 100 g a.i, ha-1 have given excellent control of leaf rust. One such spray resulted in a yield increase of 30 per cent. A spray at 400 g a.i. ha-1 increased yield by 46 per cent compared with an increase of 61 per cent in the rust-free reference. Applications around the early boot stage of crop development were the most effective. Treatment of seed with RH-124 resulted in some control of leaf rust in one season with an associated yield increase of 22 per cent. Although RH-124 appears promising, additional studies are required before use of the fungicide on commercial wheat crops would be accepted.

THE INHERITANCE OF RESISTANCE TO PUCCINIA RECONDITA IN HEXAPLOID TRITICALE

1972 ◽  
Vol 14 (3) ◽  
pp. 495-505 ◽  
Author(s):  
M. A. Quinones ◽  
E. N. Larter ◽  
D. J. Samborski
Keyword(s):  
Leaf Rust ◽  
Parental Species ◽  
Dominant Gene ◽  
Tetraploid Wheat ◽  
Puccinia Recondita ◽  
Inheritance Of Resistance ◽  
Wheat Leaf Rust ◽  
Hexaploid Triticale ◽  
Wheat Leaf ◽  
Or Genes

Rob. ex. Desm. f. sp. tritici, was studied in the hexaploid triticale cultivars 6A-190, Rosner, Armadillo, Bronco, and Toluca 160.Resistance in the triticales studied was monogenically inherited and each cultivar carried a single dominant gene. The genes conditioned resistance to races 15 and 30, and were designated genes A (6A-190), B (Rosner) C (Armadillo), D (Bronco), and E (Toluca 160). Gene A was linked in repulsion with gene C with a crossover value of 44.75 ± 1.44% and segregated independently from the other genes. Genes B and C were also independently inherited. Gene B was not linked with genes C, D, and E but observed distorted ratios with genes D and E suggested the presence of a modifying gene or genes. A similar distorted ratio was observed between genes C and D. Gene C assorted independently from gene E. No recombinants were recovered from the cross between Bronco × Toluca 160 suggesting that genes D and E were allelic or closely linked. The parental triticale cultivars Bronco and Toluca 160 carrying the genes D and E, respectively, appeared to carry modifying genes which inhibited the expression of resistance in certain crosses.The result obtained indicated that the genes governing resistance were derived from the tetraploid wheat parental species and that resistance to wheat leaf rust carried by the rye parent was not expressed in the triticale amphiploid. It was also found that genes conditioning resistance to wheat leaf rust were equally effective in conditioning resistance to rye leaf rust.

scholarly journals First Report of a Wheat Leaf Rust (Puccinia triticina) Phenotype with High Virulence to Durum Wheat in the Great Plains Region of the United States

Plant Disease ◽  
2015 ◽  
Vol 99 (1) ◽  
pp. 156-156 ◽  
Author(s):  
J. A. Kolmer
Keyword(s):  
United States ◽  
Durum Wheat ◽  
Leaf Rust ◽  
Great Plains ◽  
Puccinia Triticina ◽  
The United States ◽  
Wheat Leaf Rust ◽  
High Virulence ◽  
Wheat Leaf ◽  
Infection Types

Phenotypes of the wheat leaf rust pathogen Puccinia triticina with high virulence to tetraploid durum wheat (Triticum turgidum) are found regularly in Mexico (5), the Mediterranean region (1), the Middle East (3), and rarely in the Imperial Valley of California and the adjacent area in Arizona. Previous to 2013, these phenotypes had not been found in the Great Plains region of the United States where hexaploid, T. aestivum types of hard red winter wheat, hard red spring wheat, and durum wheat are grown. In May 2013, collections of P. triticina, the wheat leaf rust fungus identified by color, size, and shape of uredinia, were obtained from leaves of the hard red winter wheat cultivar Overley in research plots at Hutchinson, KS. A single uredinial isolate was obtained that was used in virulence testing and molecular genotyping. Urediniospores from the initial field collection were inoculated onto seedlings of the susceptible cultivar Little Club. Subsequently, single uredinia were isolated and re-increased on Little Club. The single uredinial isolate was initially inoculated to 7-day-old seedlings of 20 lines of Thatcher wheat that are near-isogenic for leaf rust resistance genes and are used in the annual virulence surveys of P. triticina in the United States (2). The phenotype of the isolate, based on virulence to the 20 differential lines, was BBBQD (2), which was identical to phenotypes of P. triticina with high virulence to durum wheat from other regions where durum wheat is commonly grown (4). This phenotype had intermediate infection type of 2+ (moderate size uredinia with chlorosis) to the line with Lr2c and high infection types of 3+ (large uredinia with no chlorosis or necrosis) to lines with genes LrB, Lr10, and Lr39/41. Overley wheat has Lr39/41. The isolate was further tested on an additional set of 27 Thatcher lines, the cultivar Gatcher with Lr27 + Lr31, and a set of 15 durum wheat cultivars that have been grown in the United States and Canada. The isolate had virulence to lines with genes Lr14b, Lr20, Lr23, Lr33, Lr44, and Lr64. Notably, the isolate had distinct low infection types to seedlings of Thatcher lines with genes Lr12, Lr13, Lr22a, Lr35, and Lr37 that are usually optimally expressed in adult plants to most P. triticina isolates. The isolate had high virulence to all of the durum wheat cultivars. The single uredinial isolate of P. triticina from Overley was also genotyped with microsatellite alleles used in previous studies with P. triticina collections from durum wheat (3). The isolate from Kansas had a highly similar genotype to other isolates of P. triticina from worldwide durum-producing regions (3). This isolate with high virulence to durum wheat most likely migrated to the southern Great Plains region from the durum-growing regions in Mexico. Cultivars such as TAM 112, Armour, Winterhawk, and Bullet with Lr39/41 and other cultivars with Overley in their pedigree are currently grown throughout the southern Great Plains. Since many of the P. triticina phenotypes with high virulence to durum wheat are virulent to Lr39/41, these cultivars may provide a pathway for the spread of these phenotypes to the major durum-producing areas of North Dakota and Saskatchewan. References: (1) H. J. Goyeau et al. Plant Pathol. 61:761, 2012. (2) J. A. Kolmer and M. A. Hughes. Plant Dis. 97:1103, 2013. (3) M. E. Ordoñez and J. A. Kolmer. Phytopathology 97:574, 2007. (4) M. E. Ordoñez and J. A. Kolmer. Phytopathology 97:344, 2007. (5) R. P. Singh et al. Plant Dis. 88:703, 2004.

A substance inducing teliospore production in wheat leaf rust, Puccinia recondita f. sp. tritici

Mycoscience ◽  
2001 ◽  
Vol 42 (3) ◽  
pp. 241-245 ◽  
Author(s):  
Tomoo Hosoe ◽  
Tatsuya Sano ◽  
Hideo Nishikawa ◽  
Koohei Nozawa ◽  
Ken-ichi Kawai ◽  
...  
Keyword(s):  
Leaf Rust ◽  
Puccinia Recondita ◽  
Wheat Leaf Rust ◽  
Wheat Leaf

Isometric virus-like particles encapsidate the double-stranded RNA found in Puccinia striiformis, Puccinia recondita, and Puccinia sorghi

1989 ◽  
Vol 67 (11) ◽  
pp. 3420-3425 ◽  
Author(s):  
Matthew J. Dickinson ◽  
A. Pryor
Keyword(s):  
Leaf Rust ◽  
Stripe Rust ◽  
Puccinia Striiformis ◽  
Puccinia Recondita ◽  
Wheat Leaf Rust ◽  
Base Pairs ◽  
Double Stranded Rna ◽  
Virus Like Particles ◽  
Puccinia Sorghi ◽  
Wheat Leaf

Isolates of Puccinia striiformis (wheat stripe rust), Puccinia recondita (wheat leaf rust), and Puccinia sorghi (maize rust) contain complexes of double-stranded RNA. In each species, there are at least 12 double-stranded RNAs ranging in size from 150 to 5000 base pairs, and the number, size, and quantitative relationships between the double-stranded RNAs are distinctive for a given species. Most, if not all, of the double-stranded RNAs in each species can be extracted from isometric virus-like particles of 40 nm in diameter purified by sucrose and (or) Cs2SO4 gradients. The data indicate that in these three species of Puccinia the double-stranded RNAs are encapsidated in virus-like particles.

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